1. Field of Invention
The present invention relates to the field of well completions. More specifically, the invention relates to a device and method for obtaining proper space-out in a well.
2. Related Art
When completing wells, there is a need to achieve a proper spacing, or space-out, between the well components. The space-out can also affect the force or weight applied to certain downhole components that can affect, among other things, proper sealing and proper function of the components.
As an example, it is necessary to perform a wet connect operation in some completions. Such an operation connects a cable or control line (e.g., fiber optic, electrical, hydraulic) contained in an upper string to a cable of same type contained in a lower string that is already part of the permanent completion in the well. Completing the wet connect requires weight to be set down onto the upper string to ensure that the connection is properly made. Likewise, the production string, or final string, that is left in the hole contains pup joints and a tubing hanger. It is necessary to have the right amount of pipe between the tubing hanger and the wet connect so that the appropriate set-down weight can be applied to make up the wet connection with the tubing hanger landed onto the wellhead.
In another example, some other types of completions are performed in two stages (a xe2x80x9ctwo stage completionxe2x80x9d). For instance, if a conventional gravel pack completion is run, the lower completion is performed with a seal bore packer as the upper most component in the lower completion string. The upper completion is then run with a seal assembly at the bottom. The upper completion can contain components such as a safety valve, permanent gauges, gas lift mandrels, and other completion jewelry. This application also requires a space out to insure the seals are engaged when the upper completed is landed.
Obtaining the proper space-out is often not difficult when the wellhead lies only a few hundred feet below the rig floor. In such cases, using the wet connect example for illustration purposes, a service string with the wet connect at its lowest point is lowered into the well in a first run into the well, and the wet connection is made with the appropriate set-down weight. With the wet connection completed, the pipe is marked on the rig floor and the service string is pulled from the well. The marking on the pipe enables space-out calculations and some sections of the service string can be replaced with pup joints and the tubing hanger assembly as appropriate. The modified production string is run in the hole in a second run into the well and the tubing hanger lands on the wellhead ensuring that an appropriate set-down weight is set onto the wet connect. This procedure also applies to the case of the two stage completion.
However, when the wellhead is further below the rig floor, a conventional space-out such as the one described above cannot be performed because of high uncertainties in length. Marking the pipe at the surface is insufficient in such a case and will not ensure that the spaceout is correct.
In general, according to one embodiment, the present invention provides an apparatus and method for achieving proper space-out of well components.
Other features and embodiments will become apparent from the following description, the drawings, and the claims.